13 files changed, 244 insertions, 4 deletions
diff --git a/README.md b/README.md
index 096082e..393c47a 100644
--- a/README.md
+++ b/README.md
@@ -8,8 +8,10 @@ Bài tập luyện tập thi Olympic, học sinh giỏi Tin học, trong đó:
 | `COCI`                 | [Giải Tin học Croatia mở rộng][0]                 |
 | `NTU`                  | [Đại học Nha Trang][1]                            |
 | `THT`                  | Hội thi Tin học trẻ                               |
-| `codeforces`           | [Codeforces][2]                                   |
-| `daily`                | [/r/dailyprogrammer][3]                           |
+| `codechef`             | [Codechef][2]                                     |
+| `codeforces`           | [Codeforces][3]                                   |
+| `cpptour`              | A Tour of C++                                     |
+| `daily`                | [/r/dailyprogrammer][4]                           |
 | `others`               | Các đề bài không rõ nguồn                         |
 | `paip`                 | Paradigms of Artificial Intelligence Programming  |
 | `sicp`                 | Structure and Interpretation of Computer Programs |
@@ -18,8 +20,9 @@ Bài tập luyện tập thi Olympic, học sinh giỏi Tin học, trong đó:
 
 [0]: http://www.hsin.hr/coci/
 [1]: http://laptrinh.ntu.edu.vn/
-[2]: http://codeforces.com/
-[3]: https://www.reddit.com/r/dailyprogrammer
+[2]: http://codechef.com/
+[3]: http://codeforces.com/
+[4]: https://www.reddit.com/r/dailyprogrammer
 
 Ở mỗi thư mục con sẽ có tệp `README.md` ghi lại đề bài. Riêng `COCI`, `NTU` và
 `codeforces` sẽ chỉ có danh sách đường dẫn tới các đề bài. Đề bài sẽ được cập
@@ -31,7 +34,9 @@ Phiên bản các trình dịch sử dụng test:
 | ----------- | ------------------ |
 | C           | GNU GCC 4.9+       |
 | Common Lisp | SBCL 1.4.8+        |
+| Lua         | Lua 5.1+           |
 | Pascal      | Free Pascal 2.6.4+ |
+| Perl 6      | Rakudo 2018.12+    |
 | Python      | Python 3.5+        |
 | Scheme      | GNU Guile 2.0.11+  |
 
diff --git a/cpptour/README.md b/cpptour/README.md
new file mode 100644
index 0000000..b60cb65
--- /dev/null
+++ b/cpptour/README.md
@@ -0,0 +1,10 @@
+A Tour of C++
+-------------
+
+These are my draft while following Bjarne Stroustrup tour to learn some C++11.
+Not that I eventually fell for the language, but I did realize that I simply
+cannot evite it forever. In fact, this is the preparation for a Python
+extension.
+
+Since the book is non-free (in either sense), I may not upload it. However,
+one could try to look for it in a *lib*rary. *Gen*erally it's available.
diff --git a/cpptour/Vector-test.cc b/cpptour/Vector-test.cc
new file mode 100644
index 0000000..b49ff85
--- /dev/null
+++ b/cpptour/Vector-test.cc
@@ -0,0 +1,20 @@
+#include <iostream>
+#include <stdexcept>
+
+#include "Vector.h"
+
+using namespace std;
+
+void
+neg_length ()
+{
+  try { Vector v (-27); }
+  catch (length_error) { cout << "it's alright" << endl; }
+  catch (bad_alloc) { cout << "BIG OOF!" << endl; }
+}
+
+int
+main ()
+{
+  neg_length ();
+}
diff --git a/cpptour/Vector.cc b/cpptour/Vector.cc
new file mode 100644
index 0000000..aa09eef
--- /dev/null
+++ b/cpptour/Vector.cc
@@ -0,0 +1,25 @@
+#include <stdexcept>
+
+#include "Vector.h"
+
+using namespace std;
+
+Vector::Vector (int s)
+{
+  if (s < 0)
+    throw length_error{"You're being negetive!"};
+  elem = new double[s];
+  sz = s;
+}
+
+double& Vector::operator[] (int i)
+{
+  if (i < 0 || size() <= i)
+    throw out_of_range{"Vector::operator[]"};
+  return elem[i];
+}
+
+int Vector::size () noexcept
+{
+  return sz;
+}
diff --git a/cpptour/Vector.h b/cpptour/Vector.h
new file mode 100644
index 0000000..c7bbc68
--- /dev/null
+++ b/cpptour/Vector.h
@@ -0,0 +1,9 @@
+class Vector {
+public:
+  Vector (int s);
+  double& operator[] (int i);
+  int size () noexcept;
+private:
+  double* elem;
+  int sz;
+};
diff --git a/cpptour/count.cc b/cpptour/count.cc
new file mode 100644
index 0000000..a047f04
--- /dev/null
+++ b/cpptour/count.cc
@@ -0,0 +1,11 @@
+#include <iostream>
+
+using namespace std;
+
+int
+main ()
+{
+  int v[] {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+  for (auto& x : v)
+    cout << x << endl;
+}
diff --git a/cpptour/enumcls.cc b/cpptour/enumcls.cc
new file mode 100644
index 0000000..2340f65
--- /dev/null
+++ b/cpptour/enumcls.cc
@@ -0,0 +1,28 @@
+#include <iostream>
+
+using namespace std;
+
+enum class Color { red, blue, green };
+enum class TraficLight { green, yellow, red };
+
+TraficLight& operator++ (TraficLight& t)
+{
+  switch (t)
+    {
+    case TraficLight::green:
+      return t = TraficLight::yellow;
+    case TraficLight::yellow:
+      return t = TraficLight::red;
+    case TraficLight::red:
+      return t = TraficLight::green;
+    }
+}
+
+int
+main ()
+{
+  Color col = Color::red;
+  TraficLight light = TraficLight::red;
+  TraficLight nxt = ++light;
+  // ugh now we test if it compiles? just wanna build some muscle memory
+}
diff --git a/cpptour/helloworld.cc b/cpptour/helloworld.cc
new file mode 100644
index 0000000..89a7f8a
--- /dev/null
+++ b/cpptour/helloworld.cc
@@ -0,0 +1,7 @@
+#include <iostream>
+
+int
+main ()
+{
+  std::cout << "Hello, World!" << std::endl;
+}
diff --git a/cpptour/myvec.cc b/cpptour/myvec.cc
new file mode 100644
index 0000000..1314730
--- /dev/null
+++ b/cpptour/myvec.cc
@@ -0,0 +1,36 @@
+#include <iostream>
+
+using namespace std;
+
+struct Vector
+{
+  int sz;       // number of elements
+  double* elem; // pointer to elements
+};
+
+void
+vector_init (Vector& v, int s)
+{
+  v.elem = new double[s];
+  v.sz = s;
+}
+
+double
+read_and_sum (int s)
+{
+  Vector v;
+  vector_init (v, s);
+  for (int i = 0; i != s; ++i)
+    cin >> v.elem[i];
+
+  double sum = 0;
+  for (int i = 0; i != s; ++i)
+    sum += v.elem[i];
+  return sum;
+}
+
+int
+main ()
+{
+  cout << read_and_sum (5) << endl;
+}
diff --git a/cpptour/square.cc b/cpptour/square.cc
new file mode 100644
index 0000000..fb14456
--- /dev/null
+++ b/cpptour/square.cc
@@ -0,0 +1,21 @@
+#include <iostream>
+
+using namespace std;
+
+double
+square (double x)
+{
+  return x * x;
+}
+
+void
+print_square (double x)
+{
+  cout << "the quare of " << x << " is " << square (x) << endl;
+}
+
+int
+main ()
+{
+  print_square (1.234);
+}
diff --git a/cpptour/static-ass.cc b/cpptour/static-ass.cc
new file mode 100644
index 0000000..837a965
--- /dev/null
+++ b/cpptour/static-ass.cc
@@ -0,0 +1,8 @@
+constexpr double C = 2999792.458;   // km/s
+
+int
+main ()
+{
+  constexpr double local_max = 160.0 / (60 * 60);
+  static_assert (local_max < C, "can't go that fast");
+}
diff --git a/cpptour/veccls.cc b/cpptour/veccls.cc
new file mode 100644
index 0000000..0162d23
--- /dev/null
+++ b/cpptour/veccls.cc
@@ -0,0 +1,32 @@
+#include <iostream>
+
+using namespace std;
+
+class Vector {
+public:
+  Vector (int s) : elem {new double[s]}, sz {s} {}  // construct a Vector
+  double& operator[] (int i) { return elem[i]; }    // random access
+  int size () { return sz; }
+private:
+  double* elem; // pointer to the elements
+  int sz;       // the number of elements
+};
+
+double
+read_and_sum (int s)
+{
+  Vector v (s);
+  for (int i = 0; i != v.size (); ++i)
+    cin >> v[i];
+
+  double sum = 0;
+  for (int i = 0; i != v.size (); ++i)
+    sum += v[i];
+  return sum;
+}
+
+int
+main ()
+{
+  cout << read_and_sum (5) << endl;
+}
diff --git a/cpptour/vecuser.cc b/cpptour/vecuser.cc
new file mode 100644
index 0000000..0eefb0e
--- /dev/null
+++ b/cpptour/vecuser.cc
@@ -0,0 +1,28 @@
+#include <cmath>
+#include <iostream>
+#include <stdexcept>
+
+#include "Vector.h"
+
+using namespace std;
+
+double
+sqrt_sum (Vector& v)
+{
+  double sum = 0;
+  for (int i = 0; i <= v.size(); ++i)
+    try { sum += sqrt(v[i]); }
+    catch (out_of_range) { cout << "Yeet!" << endl; }
+  return sum;
+}
+
+int
+main ()
+{
+  int n;
+  cin >> n;
+  Vector v (n);
+  while (n--)
+    cin >> v[n];
+  cout << sqrt_sum (v) << endl;
+}